The incorporation of electronic devices with pneumatic tire structures has been shown to yield many practical advantages. Tire electronics may include sensors and other components for obtaining information regarding various physical parameters of a tire, such as temperature, pressure, number of tire revolutions, vehicle speed, etc. Such performance information may be useful in tire monitoring and warning systems, and may even be employed with feedback systems to monitor proper tire pressure levels.
U.S. Pat. No. 5,749,984 (Frey et al.) discloses a tire monitoring system and method that is capable of determining such information as tire deflection, tire speed, and number of tire revolutions. Another example of a tire electronics system can be found in U.S. Pat. No. 4,510,484 (Snyder), which concerns an abnormal tire condition warning system.
U.S. Pat. No. 4,862,486 (Wing et al.) also relates to tire electronics, and more particularly discloses an exemplary revolution counter for use in conjunction with automotive and truck tires.
U.S. Pat. No. 7,006,946 (Tyndall) relates to the intentional inducement of specific vibrations into a tire containing a vibration sensor to transmit information to electronics associated with the sensor.
Yet another potential capability offered by electronics systems integrated with tire structures corresponds to asset tracking and performance characterization for commercial vehicular applications. Commercial truck fleets, aviation crafts and earthmover/mining vehicles are all viable industries that could utilize the benefits of tire electronic systems and related information transmission. Tire sensors can determine the distance each tire in a vehicle has traveled and thus aid in maintenance planning for such commercial systems. Vehicle location and performance can be optimized for more expensive applications such as those concerning earth-mining equipment. Entire fleets of vehicles may be tracked using RF tag transmission, exemplary aspects of which are disclosed in U.S. Pat. No. 5,457,447 (Ghaem et al.).
In the operation of commercial truck fleets, vehicle down time can be very costly, possibly resulting in the loss of an entire payload for a time-critical shipment. Tire management is one of the principal challenges for truck fleet management. Tire longevity is greatly affected by inflation pressure maintenance. If the position of a tire ID on the vehicle is known, along with the inflation pressure, then repair and replacement can be more efficiently planned and executed.
It would be beneficial in a tire-vehicle-fleet system if pressure loss could be automatically detected and such information transmitted to fleet operation management. Knowing the tire ID, the rate of pressure loss, and the position on the vehicle would permit fleet operation management to efficiently arrange the correct replacement tire size and type in an appropriate timeframe along that vehicle's route, thus minimizing down-time.
While various implementations of wheel location systems have been developed, and while various combinations of information have been wirelessly relayed from a tire or wheel assembly using conventional technologies, no design has emerged that generally encompasses all of the desired characteristics as hereafter presented in accordance with the subject technology.